1. Field of the Invention
The invention relates to a readout method performed by stripe scanning planar objects with substances emitting fluorescence radiation, a detector being provided and said fluorescence radiation being imaged onto said detector.
2. Description of the Prior Art
A device of the type mentioned herein above is known from EP 2003 076 6413 (WO 2004 013625), said device comprising a UV-source for generating fluorescence radiation, electrically charged substances being read out of a separating medium of a gel electrophoresis apparatus using a detector. The UV detector may hereby be a CCD camera, a photomultiplier, a semiconductor diode or a semiconductor diode array. The readout of larger fields using such a CCD camera is problematic inasmuch as it requires very expensive UV-optics in accordance with the size of the field. Utilizing a photomultiplier is out of the question because the scan duration with such a photomultiplier is much too long. Using semiconductor diodes or a semiconductor diode array is disadvantageous because they are too insensitive.
As already explained above, using a CCD camera to achieve fast readout of such type planar objects is out of the question because, as already discussed, it requires very expensive UV-optics. Provided one would utilize such complicated optics for scanning in order to be able to image quite large areas, scanning would still have to be sequential, meaning that the mechanical device causing either the planar object or the detector to move, must be stopped for each subimage. This places high demands on the mechanics and is moreover time intensive.
Using a photomultiplier, the scanning process is time consuming because the object must be scanned row by row. If a low-cost lamp is for example used as a lighting source, the additional problem arising is that it is not possible to focus enough light onto a sufficiently small spot of the object. As a result, a major part of the light emitted by the lamp must inevitably be eliminated by means of a pinhole.